Genetics Review

Front

What is the definition of dominant trait in genetics?

Back

A dominant trait is a genetic trait that is expressed in the phenotype even when only one copy of the allele is present.

Front

What is the definition of recessive trait in genetics?

Back

A recessive trait is a genetic trait that is only expressed in the phenotype when two copies of the allele are present.

Front

What does it mean for an individual to be heterozygous?

Back

An individual is heterozygous when they have two different alleles for a particular gene.

Front

What does it mean for an individual to be homozygous?

Back

An individual is homozygous when they have two identical alleles for a particular gene.

Front

What is a Punnett square used for?

Back

A Punnett square is a diagram used to predict the genotypes of offspring from a genetic cross.

Front

What does a half-colored symbol represent in a pedigree chart?

Back

A half-colored symbol indicates that the individual is a carrier of a recessive trait.

Front

What is the genotype for short fur in animals if shaggy fur is dominant?

Back

The genotype for short fur is homozygous recessive (tt).

Front

If shaggy fur (S) is dominant over short fur (s), what is the genotype of a shaggy furred animal that is a carrier?

Back

The genotype of a shaggy furred animal that is a carrier is heterozygous (Ss).

Front

What is the expected phenotypic ratio of offspring from a cross between two heterozygous parents (Tt x Tt) for a trait where T = tall and t = short?

Back

The expected phenotypic ratio is 3 tall : 1 short.

Front

What is the expected percentage of offspring with short fur from a cross between a heterozygous shaggy furred animal and a homozygous recessive short furred animal?

Back

The expected percentage of offspring with short fur is 50%.